[GFS2] Fix incorrect return code in rgrp.c

The following patch fixes a bug where 0 was being used as a return code
to indicate "nothing to do" when in fact 0 was a valid block location
which might be returned by the function.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/gfs2/rgrp.c

@@ -867,7 +867,7 @@ static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked)
 			break;
 		goal = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED,
 				    GFS2_BLKST_UNLINKED);
-		if (goal == 0)
+		if (goal == BFITNOENT)
 			break;
 		no_addr = goal + rgd->rd_data0;
 		goal++;
@@ -1316,7 +1316,7 @@ static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,
 				    bi->bi_len, blk, new_state);
 	}
 
-	return (blk == BFITNOENT) ? 0 : (bi->bi_start * GFS2_NBBY) + blk;
+	return (blk == BFITNOENT) ? blk : (bi->bi_start * GFS2_NBBY) + blk;
 }
 
 /**
@@ -1396,6 +1396,7 @@ u64 gfs2_alloc_data(struct gfs2_inode *ip)
 		goal = rgd->rd_last_alloc_data;
 
 	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	BUG_ON(blk == BFITNOENT);
 	rgd->rd_last_alloc_data = blk;
 
 	block = rgd->rd_data0 + blk;
@@ -1440,6 +1441,7 @@ u64 gfs2_alloc_meta(struct gfs2_inode *ip)
 		goal = rgd->rd_last_alloc_meta;
 
 	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	BUG_ON(blk == BFITNOENT);
 	rgd->rd_last_alloc_meta = blk;
 
 	block = rgd->rd_data0 + blk;
@@ -1481,6 +1483,7 @@ u64 gfs2_alloc_di(struct gfs2_inode *dip, u64 *generation)
 
 	blk = rgblk_search(rgd, rgd->rd_last_alloc_meta,
 			   GFS2_BLKST_FREE, GFS2_BLKST_DINODE);
+	BUG_ON(blk == BFITNOENT);
 
 	rgd->rd_last_alloc_meta = blk;